The story of the Flora is the story of Arthur and Hedy Hahnloser-Bühler, who built up a collection of French and Swiss art of exceptional quality between 1907 and 1936. The collection focuses on prints, sculpture and paintings by Post-Impressionist, Nabis and Fauve artists, who were among the most important artists at the turn of the 19th and 20th centuries. Another special feature of this collection is that the collector couple was on friendly terms with many of the artists, quite a few of whom visited the Flora and even created a few works here on site.

Winterthur lacked a medical facility that would have allowed inpatient treatment – Hahnlosers made this possible. As with the house, Hedy used her fortune to pay for this costly facility. She also assisted actively and looked after the patients, while Arthur took care of the operations. Because he also admitted and treated people who could hardly afford it – labourers and farmers – and often waived the costs for them, he soon became known as "the eye doctor of the poor".

In close contact with her friend, the painter and art dealer Carl Montag, who was living in Paris at the time, her view of art changed increasingly. After a visit to the Biberist collector Oscar Miller, who owned many avant-garde paintings, particularly by Cuno Amiet, and a visit to a Hodler exhibition in Interlaken, they soon ventured into new territory. In August 1907, they travelled to Stampa to visit Giovanni Giacometti. By the time they returned home, they had made a new friend and purchased a new painting, a self-portrait that had just been painted and still smelled of fresh oil paint. It was the prelude to modernism.

In addition to Vallotton, the Hahnlosers soon became interested in the other painters from the Nabis group of artists. They also got to know Pierre Bonnard, Edouard Vuillard and Ker-Xavier Roussel and acquired works by them. Another French artist they esteemed was Pierre Renoir. At the time, he was regarded as the culmination of Impressionism and was revered throughout Europe, even in Germany. Also in the Flora, he was seen as the forerunner of Bonnard and his colleagues, and as such he featured prominently in the collection of the Hahnlosers and other Winterthur residents.

Hedy Hahnloser struggled repeatedly with her health and she suffered from tuberculosis. The air and warmth of the south helped her, and so after the war the Hahnlosers bought a house in Cannes, the Villa Pauline, where they spent the winter months from then on. As the south of France was – probably not entirely coincidentally – also a popular destination for many painters, this provided the opportunity to deepen many contacts and friendships.

What makes the collection special is not only the quality of the artworks, but also the nature of their history, as they were created through direct exchange between the artists and the collector couple. This defined the character of the collection. As little as the collection focussed on stylistic or thematic aspects, it still captivates through the extensive groups of works by different artists. It was not the representative element, but the commitment to the artists that set the guidelines. There are no individual works by an artist – once Arthur and Hedy became enthusiastic about an artist and discovered their passion for him, they remained loyal to him and his work. Despite and also because of their sensitivity and taste, they allowed themselves to be guided by the artists and inspired to see things in new ways.

In 2014, the Winterthur City Council refused to subsidise the museum and it was closed. A virtue was made of necessity, and the collection went on a celebrated European tour that took it from the Hamburger Kunsthalle to the Musée Marmottan in Paris and the Albertina in Vienna. In the meantime, a solution was sought while the foundation's works were housed at the Kunstmuseum Bern for six years. Finally, the Canton of Zurich bought the Villa Flora and transferred it to the City of Winterthur on a building lease. A restoration and gentle structural extension made the Flora fit for the future. As part of the Winterthur museum concept, which also includes the Oskar Reinhart Foundation alongside the Kunstmuseum, it is now the third and newest member of the Kunst Museum Winterthur.